Marine propeller

ABSTRACT

A marine propeller which has a boss having inner and outer cylinders coaxially disposed with each other in such a manner that at least one opposing surface of the inner and outer cylinders is obliquely formed in trough shape of wedge type and the other opposing surface thereof is obliquely formed correspondingly in crest shape of wedge type, and a resilient member disposed in the gap between the oblique opposing surfaces of the inner and outer cylinders so as to integrate both the cylinders.

O United States Patent 1 1 1111 3,865,510

Yoshino Feb. 11, 1975 [54] MARINE PROPELLER 2,469,116 5/1949 Kiekhaefer 416/134 2,802,353 8/1957 Peirce 416/134 X lnvemo" Takao Y0Shm1 Japan 3,279,415 10/1966 Kiekhaefer 416/93 [73] Assignee: Kabushiki Kaisha Komat 3,744,931 7/1973 Cavanagh 416/134 UX Seisakusho, Tokyo, Japan Primary Examiner-Everette A. Powell, Jr. [22] Flled: 1973 Attorney, Agent, or FirmArmstrong, Nikaido & [21] Appl. No.: 418,023 Wagner [301 Foreign Application Priority Data [57] ABSTRACT MW 29, J an 47/113338 A marine propeller which has a boss having inner and outer cylinders coaxially disposed with each other in such a manner that at least one opposing surface of [2?] 4l6/l3 g64lh6/l69 the inner and outer Cylinders is obliquely formed in 3 trough shape of wedge yp and the other pp g 1 1e 0 earc l69 surface thereof is obliquely formed correspondingly in crest shape of wedge type, and a resilient member dis- [56] References C'ted posed in the gap between the oblique opposing sur- UNITED STATES PATENTS faces of the inner and outer cylinders so as to inte- 2,097,3l8 10/1937 Dowell 416/134 grate both the cylinders. 2,235,605 3/1941 Bugatti. 2,354,101 7 1944 Broders 416/134 6 Clams 3 Drawmg Flgures 2 6a. b e e 6 MARINE PROPELLER This invention relates to a marine propeller having a resilient member disposed between the inner and outer cylinders of its boss, and more particularly to improvements of the marine propeller which prevents the outer cylinder of the boss bearing the propulsion force of the propeller from pulling out of the inner cylinder fixed to the drive shaft of the propeller.

Heretofore, some of the conventional marine propeller, particularly the propeller for compact vessel has a resilient member such as rubber disposed between the inner cylinder of the boss fixed to the drive shaft of the propeller and the outer cylinder of the boss including blades formed therearound so as to prevent the blades from being damaged by reducing the shock with the resilient member in case where one of the blades collides with an obstacle. However, since the outer cylinder is supported through the resilient member to the inner cylinder fixed to the drive shaft, there have frequently taken place accidents that the outer cylinder was pulled out of the inner cylinder by the reaction of the propulsion force acting to the blades.

It is, therefore, an object of the present invention to provide a marine propeller which eliminates the aforementioned disadvantages of the conventional propeller and prevents the outer cylinder of the boss thereof from being pulled out of the inner cylinder of the boss even if the reaction of the propulsion force is applied with shock to the blade together with the outer cylinder of the boss.

It is another object of the present invention to provide a marine propeller which prevents the blades thereof from being damaged when shock is applied to the blade by obstacles,

According to the present invention, one preferred embodiment of the marine propeller of the invention comprises a boss having inner and outer cylinders coaxially disposed with each other in such a manner that at least one opposing surface of the inner and outer cylinders is obliquely formed in trough shape of wedge type and the other opposing surface thereof is obliquely formed correspondingly in crest shape of wedge type, and a resilient member disposed in the gap between the oblique opposing surfaces of the inner and outer cylinders so as to prevent the outer cylinder of the boss from being pulled out of the inner cylinder of the boss by the wedging action of the oblique opposing surfaces of the inner and outer cylinders of the boss.

These and other objects, features and advantages of the marine propeller according to the present invention will become more fully apparent from the following description taken in conjunction with the accompanying drawings, in which like reference numerals and characters designate corresponding parts and components and in which:

FIG. I is a longitudinal sectional view of the essential part of the propeller of the present invention;

FIG. 2 is a sectional view of the propeller taken along the line ll-II in FIG. 1; and

FIG. 3 is a view showing the method of inserting the resilient member into the boss of the propeller of the present invention.

Referring to the drawings, numeral 1 represents a boss of the propeller of the present invention, which is formed of an inner cylinder 3 having an engaging hole 2 for a drive shaft (not shown) at the center thereof and an outer cylinder 5 including blades 4 formed therearound. The outer peripheral surface of the inner cylinder 3 is formed continuously in trough shape oblique surface 6 having different oblique surfaces 60 and 6b bent at the center thereof. The inner peripheral surface of the outer cylinder 5 is formed continuously in crest shape oblique surface 7 having different oblique surfaces 7a and 7b bent at the center thereof in such a manner that when the inner cylinder 3 is coaxially inserted into the outer cylinder 4, a gap 8 of the same interval is formed between the oblique surfaces 6 and 7 of the inner and outer cylinders, respectively. A resilient member 9 such as rubber is inserted in the gap 8 between the inner and outer cylinders 3 and 5 so as to integrate the inner and outer cylinders 3 and 5.

As shown in FIG. 3, the method of inserting the resil ient member 9 between the inner and outer cylinders 3 and 5 comprises coaxially fixing the inner and outer cylinders 3 and 5 on a station 10, and press-fitting the resilient member 9 formed in annular shape in advance into the gap 8 formed between the inner and outer cylinders 3 and 5 by a pressing means 11 so as to integrate the inner and outer cylinders 3 and 5. Another method of inserting the resilient member 9 between the inner and outer cylinders 3 and 5 may comprise pouring, molten liquid resilient member into the gap 8 between the inner and outer cylinders 3 and 5 so as to integrate the outer and inner cylinders 3 and 5..

Though the outer peripheral surface of the inner cylinder 3 is formed in trough shape and the inner peripheral surface of the outer cylinder 5 is formed in crest shape in the above embodiment, it will also be appreciated by those skilled in the art that the oblique trough shape surface 6 of the inner cylinder 3 may be oppositely formed in crest shape and the oblique crest shape surface 7 of the outer cylinder 5 may be oppositely formed in trough shape so as to provide the same effect as that in the previous embodiment.

It should be understood from the foregoing description that since the marine propeller of the present invention comprises a boss 1 which is formed of an inner cylinder 3 and an outer cylinder 5 including blades 4 formed therearound in such a manner that the outer peripheral surface of the inner cylinder 3 is formed in trough or crest shape oblique surface and the inner peripheral surface of the outer cylinder 5 is formed in crest or trough oblique surface, and a resilient member disposed in the gap 8 formed between the oblique surfaces 6 and 7, respectively, even if the outer cylinder 5 is applied with the reaction of the propulsion force with respect to the inner cylinder 3 fixed to the drive shaft, the outer cylinder 5 is prevented from being pulled out of the inner cylinder 3 by the wedging action of the resilient member 9 disposed between the oblique surfaces 6 and 7 and also by both oblique surfaces 6 and 7, and even if shocking reaction of the propulsion force is applied to the outer cylinder 5 by the sudden torque change, the outer cylinder 5 may be prevented from being pulled out of the inner cylinder 3.- In addition, even if a shock is applied to the blades 4 by the obstacles, since the resilient member disposed between the inner and outer cylinders 3 and 5 softens the shock, and accordingly it is not apprehended that the blades 4 are damaged by the shock so that the softening action by the resilient member is not eliminated.

What is claimed is:

1. A marine propeller comprising a. an inner cylinder having an engaging hole in the center thereof for engaging a drive shaft, the outer surface of said inner cylinder having a circumferential trough formed therein;

b. a hollow outer cylinder having a plurality of blades projecting from the outer periphery thereof, the inner surface of said outer cylinder having a circumferential crest formed thereon, said crest corresponding to said trough, said inner and outer cylinders being aligned coaxially and spaced apart such that a gap is formed between said inner and outer cylinders and there is no direct contact between said inner and outer cylinders along the coaxially aligned surfaces; and

c. resilient means disposed in said gap, said resilient means contacting said inner and outer cylinders along the total length of said gap, said resilient means absorbing the shock generated by said propellers and operably engaging said crest and trough to prevent the separation of said inner and outer cylinders.

2. The marine propeller of claim 1 wherein said resilient means is a press fitted member of resilient material.

3. The marine propeller of claim 1 wherein said resilient means is a molded member of resilient material.

4. A marine propeller comprising .a. an inner cylinder having an engaging hole in the -b. a hollow outer cylinder having a plurality of blades projecting from the outer periphery thereof, the inner surface of said outer cylinder having a circumferential trough formed therein, said trough corresponding to said crest, said inner and outer cylinders being aligned coaxially and spaced apart such that a gap is formed between said inner and outer cylinders and there is no direct contact between said inner and outer cylinders along the coaxially aligned surfaces; and

c. resilient means disposed in said gap, said resilient means contacting said inner and outer cylinders along the total length of said gap, said resilient means absorbing the shock generated by said propellers and operably engaging said crest and trough to prevent the separation of said inner and outer cylinders.

5. The marine propeller of claim 4 wherein said resilient means is a press fitted member of resilient material.

6. The marine propeller of claim 4 wherein said resilient means is a molded member of resilient material. 

1. A marine propeller comprising a. aN inner cylinder having an engaging hole in the center thereof for engaging a drive shaft, the outer surface of said inner cylinder having a circumferential trough formed therein; b. a hollow outer cylinder having a plurality of blades projecting from the outer periphery thereof, the inner surface of said outer cylinder having a circumferential crest formed thereon, said crest corresponding to said trough, said inner and outer cylinders being aligned coaxially and spaced apart such that a gap is formed between said inner and outer cylinders and there is no direct contact between said inner and outer cylinders along the coaxially aligned surfaces; and c. resilient means disposed in said gap, said resilient means contacting said inner and outer cylinders along the total length of said gap, said resilient means absorbing the shock generated by said propellers and operably engaging said crest and trough to prevent the separation of said inner and outer cylinders.
 2. The marine propeller of claim 1 wherein said resilient means is a press fitted member of resilient material.
 3. The marine propeller of claim 1 wherein said resilient means is a molded member of resilient material.
 4. A marine propeller comprising a. an inner cylinder having an engaging hole in the center thereof for engaging a drive shaft, the outer surface of said inner cylinder having a circumferential crest formed thereon; b. a hollow outer cylinder having a plurality of blades projecting from the outer periphery thereof, the inner surface of said outer cylinder having a circumferential trough formed therein, said trough corresponding to said crest, said inner and outer cylinders being aligned coaxially and spaced apart such that a gap is formed between said inner and outer cylinders and there is no direct contact between said inner and outer cylinders along the coaxially aligned surfaces; and c. resilient means disposed in said gap, said resilient means contacting said inner and outer cylinders along the total length of said gap, said resilient means absorbing the shock generated by said propellers and operably engaging said crest and trough to prevent the separation of said inner and outer cylinders.
 5. The marine propeller of claim 4 wherein said resilient means is a press fitted member of resilient material.
 6. The marine propeller of claim 4 wherein said resilient means is a molded member of resilient material. 